Pump.



W. 0. J. GUILFOBD.

PUMP.

APPLICATION FILED JAN. 7, 1910.

Patented Oct. 10, 1911.

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UNITED ST TES PATENT OFFICE.

WILLIAM din GUILFORD, br WASHINGTON, DISTRICT or coLUMBIA.

PUMP.

Application filed January 7, 1910. Serial No. 536,914.

' the hands.

An important characteristic of my im-- provement resides in means facilitating the easy operation of the pump when used forrelatively heavy work such as in connection with vehicle tires; also the easy and delicate operationof the same when used in connection with relatively light work as required, for example, in dental work, in which latter connection I have found my pump peculiarly adapted to expand an impression device, as is more particularly set forth in the copending application executed of even date herei with.

In the accompanying drawings forming a part hereof I have illustrated a convenient embodiment of my invention, and an inspection of said drawlngs in connection with the detailed description herein contained will disclose the details and arrangement of parts of my improved pump.

In the drawings, Figure l is a perspective view of the pump, Fig. 2 is a longitudinal sectional view of the same, Fig. 3 is a transverse section on line 00- 1: of Fig. 1.

Referring more specifically to the drawings, wherein like reference characters designate corresponding parts in the several views, A designates the pump cylinder'which is conveniently of an elongated upright type B the piston adapted to be reciprocated vertically in the cylinder, and C is a supporting base having at one side an elongated foot piece D adapted .to be engaged .by one foot' of the user, to steady the pump and maintain it in operative positio E represents an inverted U-shaped piston rod, the same being formed of a pipe or tube, the inner arm e of which extends through the top a of the cylinder and is connected at b to the piston B. The open end of this arm 6 of the piston rod is closed in the active or compressingmovement of the Specification of Letters Patent.

Patented Oct. '10, 1911.

piston, designated by the arrow, by. a free valve F supported in a cage 7 and adapted to open by gravity on a reverse or upward movement of the cap\ of the cylinder is provided with a guide boxG having an upper series .of ball bezh:T ings g and a ldwer series of ball bearings g engaging the arm e of thepiston rod and facilitating free and easy movement of the same while at the, same time preventing any binding of the piston rod incident to the tilting tendency of the same under actuation of the means now to be defined. The outer or return parallel arm e of the piston rod depends downwardly outside of the casing A and through the vertical aperture h in a combined stirrup and guide H, the end of this arm a being threaded as at 7%,, for

the engagement of the clamping nuts it, h,

adapted respectively to bind upon the upper and lower surfaces of\ the member H referred to, and as clearly shown in the drawings. The lower end of the pipe or piston rod as shown at 6 air induction port, it being understood that the air is drawn through the hollow piston into the cylinder in the upward movement of the piston, as shown by the dotted arrow and forced out of the cylinder in the down- 5 ward movement of the piston through the outlet nipple I connected to any suitable conducting pipe or tube as desired.

The outer end of the member H is formed into a stirrup J provided with a foot rest j and a supporting member 3" connecting the outer edge of the same to the main body or inner portion of the member H to strengthen the stirrup, as is obvious, the member H beto offer a long, 5

ing of substantial thickness firm fastening for the piston rod passing theret-hrough. It will be noted that in operation the stirrup may project in a direction outwardly relative to the cylinder away from the foot rest I) on the opposite side of the cylinder, so that the latter may be en gaged by one of the feet to hold the device while the piston is worked in both directions by the other foot which engages the stirrup. The stirrup, however, about the cylinder, the same may assume any position desired for the ease and comfort of the user, for instance, at right angles to the foot rest or even thereabove, if desired.

The inner portion of the member H is of 110 annular configuration adapted to work freely over the cylinder A and the same piston. The top of the 60 is open to constitute an 80 being free to turn carries near its upper and lower edges respectively an upper series of ball bearings 70 and a lower series of ball bearings is, engaging the outer surface of the cylinder to facilitate easy working of the device and revent any binding of the guide constituted y this portion of the member H upon the cylinder incident to the tendency of the ,same to tilt in either direction under the op- ,eration of the laterally projecting stirrup.

By having the U-shaped piston rod of tubingthroughout, a strong single-piece structure is affored while obviating the necessity of otherwise providing air inlet passages or the weakening of a solid rod by perforating the same for the inlet of the air.

While I have herein disclosed a specific embodiment of my invention, it is to be understood that other embodiments may be resorted to Without departing from the spirit of the invention.

I claim 1. The combination with a pump cylinder having a cylindrical outer surface, a piston in said cylinder, and means for operating the piston comprising an inverted U-shaped piston rod, one arm of which is connected to the piston within the cylinder, and the other arm of which is arranged outside of the cylinder, a guide ring surrounding the pump cylinder and connected to the outer arm of the piston rod, said ring being provided with vertically separated upper and lower bearings engaging the cylinder, whereby said ring is free to' rotate around the cylinder and to slide freely thereon and binding to the ring incident to its tendency to' tilt during reciprocation is prevented, and a closed stirrup projecting from said guide rmg. o

2. In combination with the cylinder and piston of a pump, means for operating-the piston comprising an inverted U-shaped piston rod, one arm of which is connected to the piston within the cylinder, and the other arm of which is arranged outside the cylinder, a foot piece carried by said outside arm for operating the piston, a guide of substantial width for the foot piece comprising a ring secured to be moved therewith surrounding the pump cylinder, and separated upper and lower series of ball bearings in said ring engaging said cylinder to resist binding incidentto the tilting tendency of the guide in its reciprocating movements. I

3. In combination with the cylinder and piston of a pump, means for-operating the piston comprising an inverted U-shaped piston rod, one arm of. which is connected to the piston within the cylinder and the other arm of which is arranged outside the cylin-' der, a combined foot piece and uide detachably connected to said outsi e arm, said guide freely embracing the cylinder to shift thereon and provided with separated upper and lower series of ball bearings contactlng the surface of the cylinder.

4. In combination with the cylinder and piston of a pump, means for operatin the piston comprising an inverted U-shape piston rod, one arm of which is connected to the piston within the cylinder, and i the other arm of which is arranged outside the cylinder, a separately formed foot stirrup having a solid inner portion of substantial thickness carried by said outside arm, said stirrup having a foot rest and a supporting member extending upwardly and inwardly from the outer edge of the said foot rest to the upper edge of the said inner solid portion of the stirrup, and a guide formed with the stirrup, and of corresponding substantial thickness embracing the cylinder, said guide being provided with separated upper and lower series of ball bearings engaging the cylinder. j

5. In combination with the cylinder and piston of a pump, means for operating the piston comprising an inverted U-shaped piston rod, one arm of which is connected to the piston within the cylinder, and the other arm of which is arranged outside the cylinder, a stirrup carried by said outside arm, and separated upperv and lower series of ball bearings arranged in the head of the cylinder for said inner arm to prevent binding incident to the tilting tendency of the piston rod.

(S. In a device of the character described, a base, a pump cylinder supported thereon, a piston in said cylinder, means for operatin the piston comprising an inverted U-shaped piston rod, one arm of which passes through the upper head of the pump cylinder, and is connected to the piston within the cylinder and the other arm of which is arranged outside of the cylinder, separated upper and lower series of ball bearings arranged in the head of the cylinder for engaging the inner arm of the-piston rod at separated points, a relatively wide bearing ring connected to the outer arm of the piston rod and embracing the exterior of the pump cylinder, said bearing ring being provided with separated upper and lower series of ball bearings engaging the exterior of the cylinder, and a 

